diff --git a/libcxx/utils/ci/run-buildbot b/libcxx/utils/ci/run-buildbot
--- a/libcxx/utils/ci/run-buildbot
+++ b/libcxx/utils/ci/run-buildbot
@@ -310,7 +310,8 @@
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-asan.cmake" \
                    -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
-                   -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
+                   -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in" \
+                   -DCMAKE_CXX_FLAGS="-mllvm -asan-use-private-alias=1"
     check-runtimes
 ;;
 generic-msan)